Well, of course it's a good idea to double check with various output methods. But if a mix sounds good on studio monitors with a flattest possible frequency response (preferably even calibrated with an internal DSP) in an acoustically treated room, there's a very high probability it will sound good on almost anything out there. At least that's my experience.

I would reccomend one to take a look at the usual frequency response of cheap drivers or the inherent flaws of the consumer tech over time and compare it with the evolution of pop music.

Audio engineers are for sure taking all this into account, and more (: